Method of and apparatus for preparation of waste material for disposal

ABSTRACT

A hydraulic ram feeds rubbish or other material to be fragmented to a disintegrator through an enclosed passageway. A constantlyoperating hydraulic pump generates the fluid pressure to drive the ram. A sensing device monitors the current demands to the motor for driving the disintegrator and the signal from the sensing device through a transducer stops the travel of the ram and hence the feeding of material to the disintegrator when current demands of the motor reach a predetermined value and resumes the feed when the current demands decrease to normal while the output of the continuously-operating pump is bypassed through pressure relief valves to maintain a continuous pressure in the system.

United States Patent [191 [111 3,792,817 Reilly [4 51 Feb. 19, 1974 [54] METHOD OF AND APPARATUS FOR 3,528,616 9/1970 Krolopp et al 241 34 PREPARATION OF WASTE MATERIAL FOR DISPOSAL Bertram B. Reilly, 17 Briar Cliff Rd., Pittsburgh, Pa. 15102 Filed: May 5, 1972 Appl. No.: 250,665

Related US. Application Data Continuation-impart of Ser. No. 82,908, Oct. 22, 1970, Pat. No. 3,680,719.

Inventor:

References Cited UNITED STATES PATENTS Primary Examiner-Granville Y. Custer, Jr.

Attorney, Agent, or FirmParmelee, Miller, Welsh & Kratz 5 7 1 ABSTRACT A hydraulic ram feeds rubbish or other material to be fragmented to a disintegrator through an enclosed passageway. A constantly-operating hydraulic pump generates the fluid pressure to drive the ram. A sensing device monitors the current demands to the motor for driving the disintegrator and the signal from the sensing device through a transducer stops the travel of the ram and hence the feeding of material to the disintegrator when current demands of the motor reach a predetermined value and resumes the feed when the current demands decrease to normal while the output of the continuously-operating pump is bypassed through pressure relief valves to maintain a continuous pressure in the system.

11 Claims, 2 Drawing Figures Pmmemrm 3,792,817

SHEET 1 OF 2 PATENTEDFEB 1 9:914

SHEET 2 BF' 2 1 METHOD OF AND APPARATUS FOR PREPARATION OF WASTE MATERIAL FOR ms osAL This invention is a continuation-in-part of my pending application Ser. No. 82,908, filed Oct. 22, 1970, now issued as US. Pat. No. 3,680,719 granted Aug. 1, 1972, for an apparatus and method for the preparation of waste material for disposal in landfill, incineration or recycle, and relates to the controlled intermittent feeding of the material to the milling, shredding or fragmenting apparatus to prevent or reduce overloading and at the same time maintain the power input to the feeder substantially uniform, and reduce the skill and attention required of the operators in supplying waste material to be processed to the feed hoppers of such equipment.

Municipal waste generally comprises a heterogeneous mass of papers, tree branches and leaves, boxes and crates, bottles, and discarded furniture and appliances including washing machines and refrigerators, old automobile tires, etc. In order to reduce the space or volume of such material and provide a more acceptable landfill, many municipalities find it increasingly desirable to pass the material through some kind of milling or fragmenting apparatus that reduces the material to shreds or small pieces which greatly reduces the bulk or space required for hauling the waste to the dump and disposing of it, or preparing it for better sorting for the recovery of some metal or other valuables for recycling.

it has heretofore been proposed to feed the waste material to the disintegrating apparatus by a motordriven feed conveyor of some type, as a shaking table, endless belt, and in some cases where large objects are not encountered a feed screw may be used. Such feeds, and particularly the first two, are designed to work at a constant rate of speed which presupposes that the disintegrating apparatus will reduce the waste at a constant rate, which is not the case, and if the disintegrating equipment becomes choked and power demands on the motor are greatly increased, the efficiency of the disintegrator is reduced, and the feed must be manually stopped until the congestion in advance of the disintegrator is relieved. Frequent stopping and starting of large horsepower motors such as are required for feeders such as this imposes abnormal current demands and is detrimental to the life ofthe motors. Even after the current to the motor has been cut off, inertia results in drifting or over-travel. A further difficulty with such apparatus is that a constant watch must be kept by the crane Operator on the supply of waste to the feeder, since it will not tolerate more than a limited depth of material above the feeder. Usually the volume of material on the feeder is controlled by signals from a workman on the floor to the crane operator.

In my pending application Ser. No. 82,908, filed Oct. 22, 1970, US. Pat. No. 3,680,719, granted Aug. 1, 1972, there is disclosed an apparatus for removing refuse from. a bin having an Outlet passage through the front wall with a pusher operated by a hydraulic ram (as disclosed in my US. Pat. No. 3,303,947 of Feb. 14, 1967), said application disclosing means which, among other functions, may prevent a large object, such for example as an up-ended sofa, from blocking the outlet until properly repositioned.

With the present invention, the hopper and pusher arrangement of said copending application is combined with a disintegrating machine designed for reducing into fragments heavy objects, as above described, as well as rubbish and garbage generally. It further provides means for sensing the current demands on the motor for driving the disintegrator and for blocking the supply of pressure fluid to the hydraulic feed or ram when the current demands on the disintegrator become excessive so that if the disintegrator cannot keep pace with material being supplied to it, the feed will stop until the disintegrator catches up. However the motordriven pump which operates the feeder or ram continues to operate, and a bypass with a relief valve allows the pump to operate and maintain pressure in the system even when the feeder'or ram is stopped. Stopping and starting of the pump motor with the stopping and starting of the feed is avoided. In addition with a pusher driven by a ram the receiving hopper may be kept well filled with refuse so that the crane operator can devote some time to other activites and is not required to be alert for signals from an attendant on the plant floor.

The invention may be more fully understood by reference to the accompanying drawings in which:

FIG. 1 is a somewhat schematic view showing a longitudinal vertical section through the relevant portion of a disintegrating plant according to this invention; and

FIG. 2 is a schematic diagram of the operating and control system for the pusher.

In the drawings, wherein like reference numerals designate corresponding parts, the hopper and pusher arrangement are generally similar to that disclosed in US. Pat. No. 3,303,947 modified in accordance with the addition disclosed in my said copending application, but as here disclosed the plant, instead of being an incinerator plant, is arranged to disintegrate by shredding, crushing, grinding, beating, as in a hammermill, or other machine to reduce municipal waste or other material to fragments.

There is a building, designated generally as 2, having side walls 3 along which are rails 4 for a traveling crane, schematically indicated at 5.

There is a bin or hopper 6 as shown in my said application and patent having spaced parallel side walls 7, a rear end wall 8 and a metal bottom 9 above a permanent floor structure 10. The front end of the hopper is open across the full width of the hopper between the side walls 7 and from the metal bottom 9 to a horizontal cover plate 11, here shown at the level of the top of the bin.

There is a motor-operated slow-rotating toothed roll 12 at the top of the open forward end of the bin, which in the operation of the plant as here shown, turns in a counterclockwise direction, shown by the arrow. It has staggered rearwardly-tapering teeth 12a on its periphery and there is a toothed bar or comb 13 that extends down tangentially to the periphery of the roll with the teeth arranged to pass between the teeth of the comb 13, all as described in said copending application.

Beyond this open end of the bin there is a confined passage 14, the top of which is provided by the horizontal plate 1 l, and it has side walls 15 which are flush with the side walls 7 of the bin or hopper and a bottom 9a which is an extension of the bottom plate 9 of the bin.

The forward or left end of this passage as shown in the drawing turns downwardly in a kind of enclosed chute-like portion 14a that opens into the housing 16 of the disintegrator designated generally as 17. For purposes of illustration there is here schematically indicated a commercial form of rotary impactor type of apparatus having a motor-driven rotor 18 with peripheral ripping teeth 19 which are also designed to hurl material to be reduced in volume against anvil or impact plates 20 that are more or less yieldably held in the position indicated by hydraulic mechanisms. This impactor forms no part per se of the invention and. could be replaced by any one of a number of other types of motor-driven disintegrators designed to fragment bulky waste such as wardrobes, desks, bed-steads, cartons and crates, as well as less bulky material, all comprising typical day-in and day-out municipal waste. There is an advantage, however, in having the downwardly-sloping chute-like portion 140 so that the material moves into the machine by gravity.

Various types of machines useful for this purpose may hurl fragments of cast iron or other metal or hard material shrapnel-like in all directions, and in addition to reinforcing bars 21 on the enclosure plates forming the passage to resist damage, there is shown a swinging door type of barrier 22 in the passage 14 hinged to the top plate 11 forwardly of the toothed roll 12. It is arranged to be pushed forwardly and upwardly by waste material moving into the passage 14, but it forms a closure against the escape of such fragments when the mass of material in the passage or bin is insufficient to provide protection against the escape of such flying fragments.

, The fragmented waste material is discharged from the bottom of the impactor for removal and disposition in the intended manner.

The material is fed from the bottom of the bin into the disintegrator by a reciprocating pusher 25 as disclosed in my said US. Pat. No. 3,303,947. in FIG. 1 the pusher is shown in its most extended position at the left limit of its travel and the dotted line position shows its opposite limit of travel. It is moved by a piston rod 26 with a piston (not shown) in a fluid pressure cylinder 27, the assembly comprising a hydraulic ram. There is an apron 28 extending rearwardly from the top edge of the pusher over the piston rod to a position under the enclosure at the back wall of the bin and it is supported on rollers 29, as explained in said patent. The arrangement is such that as the pusher moves material at the bottom of the bin ahead of it, the material behind the pusher will rest on the apron above the bottom plate 9, and when the pusher retracts the material will be forced off the apron by an inclined portion 8a of the back wall 8 and fall onto the bottom of plate 9 to be subsequently pushed out in a succeeding cycle of operation.

Referring now to FIG. 2 of the drawings, the heavy lines indicate hydraulic circuits for the hydraulic ramcylinder 27 and the lighter lines are electric circuits.

The hydraulic ram 27 has a pipe line 30 at one end through which fluid pressure is supplied to force the ram forward or to the left as viewed in the drawing and to provide for the outflowof hydraulic fluid when the ram is-being retracted. There is a similar pipe 31 at the other end of the. cylinder 27 that provides for the escape of fluid when the ram is being driven forward and through which pressure fluid is supplied to force the ram back or toward the right as viewed in the drawing. Pipe 30 leads to a four-way or flow-reversing valve unit 32 of a known type and pipe 31 also connects with this unit.

A fluid pressure supply line 33 leads from a motordriven pump 34 to the valve unit 32 and pipe 35 leads from the valve unit 32 to a reservoir 36 from which liquid flows to the pump 34 through connecting pipe 37. There is a bypass connection 38 between the fluid pressure pipe 33 and the return line 35 with a pressure relief valve 39 therein. The relief valve, which for example may be spring-loaded, serves to bypass fluid from line 33 to 35 when the pump is operating but pressure fluid is not being supplied to either end of the cylinder in an amount equal to the output of the pump, as hereinafter described.

Pressure fluid from the pump is of course directed by the valve unit 32 into pipe 30, and at this time liquid may flow from the other end of cylinder 27 through the return lines 31 and 35 to the reservoir. When valve unit 32 is reversed pressure fluid is directed into the pipe 31 and line 30 is then in communication with return line 35. If valve unit 32 is in a neutral or closed position no liquid is supplied to or escapes from either of the pipes 30 and 31 and the liquid under pressure from the pump is bypassed through bypass line 38 and pressure relief valve 39 to the reservoir.

ln pipe 30 there is an adjustable flow control valve 40 around which is shunted a'one-way bypass 41 in which is a check valve 42 that allows liquid to flow freely to the return line 35 and reservoir 36 when four-way valve 32 is in a position to effect movement of the ram toward the right. However, when pressure liquid is supplied to the right end of cylinder 27, the flow is controlled by the flow control valve 40, which, for example, may be a needle valve. This serves to regulate the speed at which the ram moves toward the left and hence regulates the rate of feed of material from the bin to the disintegrator.

An accumulator, such as a weight or spring-biased accumulator here shown with a weight W, is connected with the pump outlet 33 through line 44, and there is also an adjustable flow control valve 45 in line 44. This accumulates pressure fluid during the slow forward travel of the ram for use in efiecting its quick return and thereby allows the use of a smaller pump.

The four-way valve unit as here shown in diagram is of a known type wherein the valve element is springbiased to a neutral, closed position and is moved in one direction or the other by opposed electromagnets or solenoids, solenoid 50 being for operating the valve to admit pressure fluid to line 30, and solenoid 51 for admitting pressure fluid to line 31 and allowing back flow through pipe 30. There are mechanically connected limit switches, here schematically indicated as 52 and 53 at opposite ends of'thecylinder 27 (although in practice they are physically located to be engaged by the travel of the ram) and so arranged that when 50 is open, as here indicated, 51 is closed, and vice versa.

The contact 52a of switch 52 leads through wire 54 to one side of solenoid 50 and the contact 5130 leads through wire 55 to one side of solenoid 51. The other terminals of these solenoids connect to a common line 56 leading from a source of operating current (not shown).

The movable contacts of limit switches 52 and 53 are normally connected through wire 57 to the central contact 58 of a three-contact switch 59. With switch 59 closed on contact 58, as shown, current may flow from a common supply line 60 to the switches 52 and 53. By manually moving switch 59 to contact 58' the current path to the limit switches is opened but closed from contact 58' through line 61 to line 54, thereby energizing solenoid 50 by manual selection only. Likewise, by manually moving switch 59 to contact 58", both limit dwitches are de-energized and a circuit is closed through wire 62 and line 55 with solenoid coil 51. This switch may have a fourth position where all circuits are open, but for purpose of simplicity there is shown a manual switch at 63 that may completely de-energize the electrical system.

Line 60 may be directly connected to one terminal of the power source, line 56 being connected to the other, through a manual switch 64 but normally for the purpose of this invention switch 64 connects to line 60 through an automatic switch apparatus designated generally as 65. v

The motor for driving the disintegrator in a plant such as here contemplated will be a high power motor, perhaps of the order of 1,000 horsepower or more. It is schematically indicated at 70 as being operated from a three-phase alternating current source. According to this invention means is indicated at 71 for detecting variations in the power requirements for the motor 70 and generating a signal. The apparatus 65 includes a transducer responsive to this signal to open switch element 65a in said apparatus to thereby de-energizeboth solenoids 50 and 51 so that the four-way valve will immediately go to neutral position and instantly stop the operation of the ram. This would normally occur only when the ram is feeding material forward and thereby provide relief for the disintegrator. The inductive current flow-detecting means 71 and transducer and switch arrangement 65-65a is per se not new and is employed in other industries. Normally the disintegrator will work itself clear of the congestion, thus reducing the disintegrator motor current so that switch 65a will close to resume normal feeding of material from the bin to the disintegrator. However, when necessary, switch 64 can be shifted to open the circuit through unit 65 and then switch 59 can be manually operated to work the ram back and forth to perhaps relieve some obstruction in the material feed.

The motor for driving the pump 34 is also a heavyduty motor. By reason of the bypass 38-39 the stopping and starting of the feed does not require stopping and starting of this motor which runs continuously during operation of the disintegrator. Therefore frequent stopping and starting of the feeder is not detrimental to the equipment and the bin may be heaped full with rubbish, so that perhaps the craneman may perform other duties and replenish the supply in the hopper at intervals of fifteen minutes or more, rather than requiring more or less constant communication between the craneman and an operator on the plant floor.

Generally stated, the invention provides for the intermittent feeding of material to be disintegrated in the manner herein described by regulating the feed according to the current demands of the motor which drives the disintegrator wherein the feeder is actuated through a hydraulic pressure system having a constantly-operating pump that supplies the pressure fluid to the feeder and wherein the pressure fluid is bypassed through pressure relief means when the material feed is interrupted. Specifically a hydraulic ram feeds material to a power-operateddisintegrator and the movement of the ram is controlled by monitoring means for the current flow to the motor which drives the disintegrator, and the fluid pressure-generating pump for moving the ram has a substantially constant output at all times the system is in operation, even though the feeder operates intermittently. The use of a pusher as herein disclosed is enabled to feed the heterogeneous municipal waste to the disintegrator more uniformly by reason of this power-drivenroller 12 at the top of the inlet to the passage 14, and the separation which it effects between the material being pushed forward-and the material in the bin. Normally this roll rejects enough material entering the passageway so that the remainder will normally move sufficiently freely through the passageway to move down the terminal chute portion 14a of the passage into the disintegrator by gravity.

I claim:

1. In the process of reducing heterogeneous waste material to fragments by delivering the same from a bin through an enclosed passage to a disintegrator operated by an electric motor, the steps ,of:

a. heaping the waste material in a receiving bin,

b. pushing material at the bottom of the bin into the passageway by a hydraulic ram, and

c. intermittently moving the ram to vary the rate of feed with variations in the resistance encountered by the disintegrator to fragmenting the material delivered to it.

2. The method of reducing heterogeneous waste material to fragments as defined in claim 1 in which the intermittent travel of the ram is controlled by sensing an increase or decrease in the current demands of said electric motor to shut off or open the supply of pressure liquid to said hydraulic ram as the current demands of said motor increase above or decrease from a higher to a predetermined'level.

3. The method defined in claim 1 wherein excessive compaction of material being pushed from the bin into the passageway and subsequent expansion of the material in the passageway is at least in part relieved by forcing back into the bin some of the material at the top of the mass moving into the entrance to the passageway.

4. In the process of reducing heterogeneous waste material comprising compactable municipal waste as defined in claim 3 wherein the passageway leading from the bin is horizontal and thereafter slopes downwardly to the disintegrator wherein sufiicient material is rejected from entering the passageway to normally move with sufficient freedom through the passageway to move down said slope to the disintegrator by gravity.

5. In the process of reducing rubbish and other municipal waste material to fragments by delivering the material from a bin through an enclosed passage to a disintegrator driven by an electric motor, the steps of:

a. loading the waste material into a receiving bin,

b. feeding the material from the bin through an enclosed passage to a disintegrator by feeding means actuated by fluid pressure,

0. interrupting the feeding of the material by said feeding means when the current demands on the motor which drives the disintegrator exceeds a predetermined value and resuming it when the current demands decrease to a normal level, and

d. maintaining a substantially constant fluid pressure for actuating said feeding means irrespective of whether the feeding of the material is taking place or has been interrupted.

6. The method defined in claim wherein the feeding of the material from the bin is effected by a fluid pressure ram actuated by a motor-driven fluid pressure pump in a closed circuit with pump inlet and outlet connections and wherein fluid from the pump outlet is bypassed from the pump outlet to the inlet through pressure-maintaining relief valves when the feeding of material by the fluid pressure ram is stopped by an increase in the current demands on the disintegrator driving motor.

7. An apparatus for disintegrating heterogeneous material into fragments of a predetermined maximum size which comprises:

a. a material-receiving bin,

b. a closed discharge passage leading from the bin,

c. a disintegrator into which material to be fragmented is discharged'from said passage,

d. an electric motor for driving the disintegrator,

e. means driven by fluidpressure for feeding material from the bin into the passageway,

f. a constantly-operating motor-driven closed circuit fluid pump system with outlet and inlet connections for supplying fluid under pressure to said material feeding means and receiving return fluid therefrom,

g. valve means responsive to the current demands of the disintegrator driving motor for controlling the supply of fluid pressure to said material feeding means to interrupt the operation thereof upon a predetermined increase in the power demand of said disintegrator driving motor and resuming the operation thereof when said current demand returns to normal, and

h. pressure-maintaining relief valve means arranged to bypass pressure fluid from the pump outlet connection to the pump fluid return connection while maintaining operating pressure in the system when the operation of the feed means is interrupted.

8. Apparatus as defined in claim 7 wherein the feeding means is a hydraulic ram.

9. Apparatus as defined in claim 7 wherein the feeding means is a hydraulic ram at the bottom of the bin arranged to push material from the lower portion of the bin into said passageway.

10. Apparatus as defined in claim 9 in which there is means at the entrance of said passageway where it opens into the bin for rejecting some of the material at the top of the mass being pushed into the passageway sufficiently to normally allow relatively free movement of the material between the entrance to the passageway and the disintegrator.

11. Apparatus as defined in claim 10 wherein at least a portion of the passageway remote from the entrance is sloped downwardly into the disintegrator sufficiently to normally induce gravity feed of the material through the downwardly-sloped portion of the passageway into the disintegrator. 

2. The method of reducIng heterogeneous waste material to fragments as defined in claim 1 in which the intermittent travel of the ram is controlled by sensing an increase or decrease in the current demands of said electric motor to shut off or open the supply of pressure liquid to said hydraulic ram as the current demands of said motor increase above or decrease from a higher to a predetermined level.
 3. The method defined in claim 1 wherein excessive compaction of material being pushed from the bin into the passageway and subsequent expansion of the material in the passageway is at least in part relieved by forcing back into the bin some of the material at the top of the mass moving into the entrance to the passageway.
 4. In the process of reducing heterogeneous waste material comprising compactable municipal waste as defined in claim 3 wherein the passageway leading from the bin is horizontal and thereafter slopes downwardly to the disintegrator wherein sufficient material is rejected from entering the passageway to normally move with sufficient freedom through the passageway to move down said slope to the disintegrator by gravity.
 5. In the process of reducing rubbish and other municipal waste material to fragments by delivering the material from a bin through an enclosed passage to a disintegrator driven by an electric motor, the steps of: a. loading the waste material into a receiving bin, b. feeding the material from the bin through an enclosed passage to a disintegrator by feeding means actuated by fluid pressure, c. interrupting the feeding of the material by said feeding means when the current demands on the motor which drives the disintegrator exceeds a predetermined value and resuming it when the current demands decrease to a normal level, and d. maintaining a substantially constant fluid pressure for actuating said feeding means irrespective of whether the feeding of the material is taking place or has been interrupted.
 6. The method defined in claim 5 wherein the feeding of the material from the bin is effected by a fluid pressure ram actuated by a motor-driven fluid pressure pump in a closed circuit with pump inlet and outlet connections and wherein fluid from the pump outlet is bypassed from the pump outlet to the inlet through pressure-maintaining relief valves when the feeding of material by the fluid pressure ram is stopped by an increase in the current demands on the disintegrator driving motor.
 7. An apparatus for disintegrating heterogeneous material into fragments of a predetermined maximum size which comprises: a. a material-receiving bin, b. a closed discharge passage leading from the bin, c. a disintegrator into which material to be fragmented is discharged from said passage, d. an electric motor for driving the disintegrator, e. means driven by fluid pressure for feeding material from the bin into the passageway, f. a constantly-operating motor-driven closed circuit fluid pump system with outlet and inlet connections for supplying fluid under pressure to said material feeding means and receiving return fluid therefrom, g. valve means responsive to the current demands of the disintegrator driving motor for controlling the supply of fluid pressure to said material feeding means to interrupt the operation thereof upon a predetermined increase in the power demand of said disintegrator driving motor and resuming the operation thereof when said current demand returns to normal, and h. pressure-maintaining relief valve means arranged to bypass pressure fluid from the pump outlet connection to the pump fluid return connection while maintaining operating pressure in the system when the operation of the feed means is interrupted.
 8. Apparatus as defined in claim 7 wherein the feeding means is a hydraulic ram.
 9. Apparatus as defined in claim 7 wherein the feeding means is a hydraulic ram at the bottom of the bin arranged to push material from the lower portion of the bin into said passageway.
 10. APparatus as defined in claim 9 in which there is means at the entrance of said passageway where it opens into the bin for rejecting some of the material at the top of the mass being pushed into the passageway sufficiently to normally allow relatively free movement of the material between the entrance to the passageway and the disintegrator.
 11. Apparatus as defined in claim 10 wherein at least a portion of the passageway remote from the entrance is sloped downwardly into the disintegrator sufficiently to normally induce gravity feed of the material through the downwardly-sloped portion of the passageway into the disintegrator. 